1. Field of the Invention
The present invention relates to a capsule endoscope, capsule endoscopic system, and endoscope control method. More particularly, the present invention relates to a capsule endoscope in which plural image pickup units are incorporated, and of which handling of acquired images can be facilitated, and a capsule endoscopic system, and endoscope control method.
2. Description Related to the Prior Art
A capsule endoscope is known in the medical field for diagnosis. A small capsule casing of the capsule endoscope contains an image pickup unit, a light source and the like. In the diagnosis, at first a patient is caused to swallow the capsule endoscope. While the light source illuminates a target region on inner surfaces of a gastrointestinal tract in the body, the image pickup unit photographs the target region. Image data are obtained, and transmitted to a receiver. A flash memory in the receiver is accessed to store the image data successively. During or after the inspection, image data are retrieved in a workstation as managing apparatus, for diagnosing images displayed on a display panel.
A single head type of the capsule endoscope includes a single image pickup unit, as widely known in the art. It is likely that lesions of the target region may be missed in the image pickup due to the single direction of the image pickup. In view of preventing the missing, a multi head type of the capsule endoscope including a plurality of image pickup units is suggested, for example U.S. Pat. Pub. 2005/004474 (corresponding to JP-A 2005-503182) and JP-A 2006-068534.
U.S. Pat. Pub. 2005/004474 (corresponding to JP-A 2005-503182) discloses the capsule endoscope including a mirror and other optical elements to photograph a scene of the front or rear or the right or left. JP-A 2006-068534 discloses the capsule endoscope having two image pickup units positioned in the front and rear for alternately picking up and image to prevent missing in imaging recording.
A frame rate, or the number of frames per unit time in the image pickup, is 2 fps (frame per second). Expected total time required for the diagnosis is 8 hours or more. An amount of image data stored in the receiver will be excessively large. If medical staff wishes to read all images after the inspection for diagnosis, there is a problem of requiring considerable time.
The use of the capsule endoscope is characterized in minimized physical stress to the body of the patient in comparison with diagnosis with an endoscope of the widely used steerable type. Enhanced use of the capsule endoscope is expected in the future techniques in the medicine. There is requirement of precision and rapidity in reading images of the target region for observation of lesions recently discovered in the inspection or having had surgical operation.
The use of the multi head type in U.S. Pat. Pub. 2005/004474 (corresponding to JP-A 2005-503182) and JP-A 2006-068534 is effective in preventing missing in the image pickup. Precision in the observation of the target region may be higher than that in the single head type. However, the amount of image data is two times as high as that of the single head type. The reading of the target region cannot be completed in a short time.